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CHAPTER 1
INTRODUCTION
1.1 Research Background
Demand for the next generation to produce high performance and cost effective aircraft, has motivated the aerospace industry to use new aircraft structural design and non-
traditional materials Izamshah et al. 2011. To replace the large number of assembled component, aircraft structure are designed with one piece flow of monolithic component.
Sridhar Babu P. 2013 found that monolithic thin-wall components are one piece, with high strength to weight ratios, lighter, less expensive and more accurate components
which are machined approximately up to 95 of material from prismatic blanks. Machining of monolithic components involves several thin-wall flange and rib sections as
shown in Figure 1.1. According to Ding et al. 2011, thin-wall machining of monolithic structural components allows for higher quality and reduce the manufacturing times which
impact organization issues including Just-In-Time JIT manufacturing and inventory.
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Figure 1.1: Aerospace monolithic component. Retrieved from http:www.autindustries.com
Tongyue et al. 2010 demonstrated, deformation is occur in the machining of thin-wall part which resulting a dimensional surface error, due to the poor stiffness of thin-wall
feature. The dimensional surface error is caused generally by the deflection of the thin- wall workpiece and the end mill tool during milling, which results in variation of the tool
radius immersion.
According to Izamshah et al. 2013, end mill geometrical features effect on the cutting performance such as the cutting forces, quality of machined surfaces, shape accuracy,
cutting edge wear and tool life. Peterka et al. 2010 have added that the deflection and chatter vibration of the workpiece in milling a thin-walled structure is due to low stiffness,
had a negative effect on the geometric accuracy and surface integrity. Therefore, it is necessary to select optimal cutter features when considering those effects. The geometrical
feature of end mills includes the helix angle, number of flutes, rake angle and clearance angle. Each of the geometric features has their own specific function and need to be
modelled and simulate using the finite element analysis method to effectively predict the machining surface errors.
Finite element analysis FEA has been largely implemented in simulation of the machining process. In this project FEA based simulation is used to predict the machining
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performance based on the cutter helix angle and number of flutes when milling of thin- wall component.
1.2 Problem Statement Current Technique in Machining Thin-Wall
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